000
AXPZ20 KNHC 042200
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED JUL 04 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...SPECIAL FEATURE... 
TROPICAL DEPRESSION FOUR-E CENTERED NEAR 13.5N 107.8W AT 04/2100 
UTC MOVING WNW 11 KT. ESTIMATED MINIMUM CENTRAL PRES IS 1005 MB. 
MAXIMUM SUSTAINED WIND SPEED IS 30 KT GUST TO 40 KT. SEA LATEST 
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 
KNHC FOR MORE DETAILS. THE DEPRESSION IS FORECAST TO REACH 
TROPICAL STORM INTENSITY NEAR 14.0N 109.3W TONIGHT AND HURRICANE 
INTENSITY BY SAT MORNING. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS REMAINS SPLIT AS A RESULT OF A BREAKDOWN 
EVENT WHICH INCLUDED TROPICAL DEPRESSION FOUR-E AS ONE OF THE 
VORTICES. ONE PART OF THE MONSOON TROUGH EXTENDS FROM 09N84W TO 
09N98W. THE SECOND PART OF THE MONSOON TROUGH THEN RESUMES W OF 
TROPICAL DEPRESSION FOUR-E AT 12N113W TO 07N128W THEN 
TRANSITIONS TO AN ITCZ AXIS TO BEYOND 05N140W. SCATTERED 
MODERATE TO STRONG CONVECTION WAS NOTED FROM 04N TO 12N BETWEEN 
86W AND 96W. SCATTERED MODERATE ISOLATED STRONG IS FROM 06N TO 
14N BETWEEN 114W AND 119W.

...DISCUSSION...

HIGH PRESSURE 1032 MB CENTERED NEAR 37N154W HAS RIDGE EXTENDING 
SE TO NEAR 22N118W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND 
LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS MAINTAINING A 
SMALL AREA OF FRESH 20 KT TRADES FROM 16N TO 21N W OF 135W. THIS 
RIDGE WILL PERSIST OVER THE NEXT 48 HOURS MAINTAINING THE AREA 
OF FRESH TRADES. 

THE MONSOON TROUGH IS VERY ACTIVE E OF 95W AS A RESULT OF A 
COMPLEX INTERACTION BETWEEN A TROPICAL WAVE...THE TOPOGRAPHY OF 
CENTRAL AMERICA AND THE MONSOON TROUGH. THE TROPICAL WAVE IS 
STILL E OF CENTRAL AMERICA...AND THUS FAR THE INTERACTION HAS 
BEEN MAINLY SEEN THROUGH AN INCREASE IN THE PAPAGAYO JET AND AN 
INCREASE THE HORIZONTAL EXTENT OF THE MONSOON TROUGH. BASED ON 
THE LATEST MODEL GUIDANCE...AS THE TROPICAL WAVE MOVES ACROSS 
CENTRAL AMERICA OVER THE NEXT DAY...A MORE SIGNIFICANT INCREASE 
IN LOW LEVEL VORTICITY IS EXPECTED WITHIN THE MONSOON TROUGH. 
MODELS DEPICT THAT THIS WILL HELP DEVELOP A TIGHTER SURFACE 
CIRCULATION EMBEDDED WITHIN THE MONSOON TROUGH. THIS SURFACE 
CIRCULATION WILL THEN DRIFT WESTWARD WITH THE BACKGROUND 
ENVIRONMENT EXPECTED TO BE FAVORABLE FOR GRADUAL DEVELOPMENT. IT 
WILL BE INTERESTING TO CONTINUE WATCHING THIS AREA OVER THE NEXT 
SEVERAL DAYS.  

$$
AL